isdn: capi: dead code removal

The staging isdn drivers are gone, and CONFIG_BT_CMTP is now
the only user. This means a lot of the code in the subsystem
has no remaining callers and can be removed.

Change the capi user space front-end to be part of kernelcapi,
and the combined module to only be compiled if BT_CMTP is
also enabled, then remove the interfaces that have no remaining
callers.

As the notifier list and the capi_drivers list have no callers
outside of kcapi.c, the implementation gets much simpler.

Some definitions from the include/linux/*.h headers are only
needed internally and are moved to kcapi.h.

Acked-by: David Miller <davem@davemloft.net>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20191210210455.3475361-2-arnd@arndb.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 13 insertions, 1 deletions

diff --git a/drivers/isdn/capi/capi.c b/drivers/isdn/capi/capi.c
index 1675da34239b..85767f52fe3c 100644
--- a/drivers/isdn/capi/capi.c
+++ b/drivers/isdn/capi/capi.c
@@ -39,7 +39,9 @@
 #include <linux/isdn/capiutil.h>
 #include <linux/isdn/capicmd.h>
 
-MODULE_DESCRIPTION("CAPI4Linux: Userspace /dev/capi20 interface");
+#include "kcapi.h"
+
+MODULE_DESCRIPTION("CAPI4Linux: kernel CAPI layer and /dev/capi20 interface");
 MODULE_AUTHOR("Carsten Paeth");
 MODULE_LICENSE("GPL");
 
@@ -1412,15 +1414,22 @@ static int __init capi_init(void)
 {
 	const char *compileinfo;
 	int major_ret;
+	int ret;
+
+	ret = kcapi_init();
+	if (ret)
+		return ret;
 
 	major_ret = register_chrdev(capi_major, "capi20", &capi_fops);
 	if (major_ret < 0) {
 		printk(KERN_ERR "capi20: unable to get major %d\n", capi_major);
+		kcapi_exit();
 		return major_ret;
 	}
 	capi_class = class_create(THIS_MODULE, "capi");
 	if (IS_ERR(capi_class)) {
 		unregister_chrdev(capi_major, "capi20");
+		kcapi_exit();
 		return PTR_ERR(capi_class);
 	}
 
@@ -1430,6 +1439,7 @@ static int __init capi_init(void)
 		device_destroy(capi_class, MKDEV(capi_major, 0));
 		class_destroy(capi_class);
 		unregister_chrdev(capi_major, "capi20");
+		kcapi_exit();
 		return -ENOMEM;
 	}
 
@@ -1455,6 +1465,8 @@ static void __exit capi_exit(void)
 	unregister_chrdev(capi_major, "capi20");
 
 	capinc_tty_exit();
+
+	kcapi_exit();
 }
 
 module_init(capi_init);